Vacuum distillation device for extracting lithium from residues

Abstract

The invention specifically provides a vacuum distillation device for extracting lithium from residues, the distillation device comprises a distillation retort, a medium-temperature resistance furnace and a furnace core assembly, the distillation retort comprises an evaporation area, a first-stage condensation area and a second-stage condensation area, and the evaporation area, the first-stage condensation area and the second-stage condensation area respectively correspond to areas for evaporating different components in the residues, condensing metal lithium and condensing oil; the medium-temperature resistance furnace is located on the outer side of the evaporation area and can provide different heating temperatures for evaporation; and the furnace core assembly is positioned inside the distillation retort. By controlling different temperatures of the medium-temperature resistance furnace and setting partition condensation, oil, metal lithium and electrolyte in the residues can be collected in a classified manner by utilizing the saturated vapor pressure difference of different substances; meanwhile, the detachable structural design is adopted, the evaporation tank can be separated from the furnace core, the charging amount of the evaporation tank is increased, and meanwhile charging operation is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of extracting metals from residues, and in particular to a vacuum distillation device for extracting metallic lithium from lithium residues. Background Art

[0002] The lithium residue produced by nuclear power plants is the residue after metal refining. Its main components are metals, electrolytes, oils and impurities. The metallic lithium in it needs to be recovered and reused.

[0003] At present, lithium residues are recycled using a water digestion process. The residue is manually thrown into a storage tank, and water is directly sprayed on the residue or water is added to the storage tank in advance. The digested digestion liquid is then degreased, purified, and dried. In this method, the metal reacts violently with water and releases a large amount of flammable gas. If the hydrogen content in the storage tank is too high, an explosion may occur, causing loss of life and property. In order to reduce the safety risks in the digestion process, gas replacement and vacuuming are required after each feeding, and the one-time feeding amount cannot exceed 300g. At the same time, in order to ensure that the input residues can react completely, each feeding time needs to be separated by 50-60 minutes, and the digestion efficiency is low. At the same time, the digestion liquid after digestion needs to be filtered through a filter cloth to remove the floating oil on the surface, and then the digestion liquid is purified by acid, and finally dried to obtain the electrolyte raw material. The whole process mainly relies on manual operation, which is difficult to operate, has a large workload, a long one-time processing time, and a large drying energy consumption. Summary of the Invention

[0004] The purpose of the present invention is to provide a vacuum distillation device for extracting lithium from residue, which can solve the problems of low efficiency and great difficulty in operation in the current practical application of extracting lithium from residue.

[0005] The technical solution of the present invention is as follows: a vacuum distillation device for extracting lithium from residue, the distillation device comprising: a distillation tank, a medium-temperature resistance furnace and a furnace core assembly, the distillation tank comprising an evaporation zone, a primary condensation zone and a secondary condensation zone, which respectively correspond to the regions for different components in the evaporated residue, condensed metallic lithium and condensed oil; the medium-temperature resistance furnace is located outside the evaporation zone and can provide different heating temperatures for evaporation; the furnace core assembly is located inside the distillation tank.

[0006] Furthermore, the medium-temperature resistance furnace is divided into two parts, the upper and lower cover plates, the part in contact with the distillation tank is a hard insulation layer, and the side wall of the insulation layer is installed with 12 nickel-chromium alloy heating belts, which can heat the evaporation zone.

[0007] Furthermore, the furnace core assembly includes an evaporation component and a condensation component. The evaporation component is located in the evaporation zone and includes an evaporation crucible. The evaporation crucible is used to place residue, and the maximum loading capacity is 6 kg.

[0008] Furthermore, the condensation components of the furnace core assembly include a heat insulation sheet, a condensation cover and an oil cooling area.

[0009] Furthermore, the number of the thermal insulation sheets is 1-6, and an electrolyte collector is connected to collect the condensed electrolyte.

[0010] Furthermore, the condensation hood is located in the primary condensation area and is designed as an opening with an inclination angle of 3-10 degrees, which is used to collect the condensed metallic lithium vapor. A vacuum tank is connected below it, and the condensed metallic lithium melt can flow into the vacuum tank along the conduit to extract the metallic lithium.

[0011] Furthermore, the oil cooling zone is located in the secondary condensation zone, and an oil collection tank is connected below the oil cooling zone to collect the condensed oil vapor.

[0012] Furthermore, a furnace core is connected between the condensation hood and the oil cooling area, and the furnace core is located in the transition area of the distillation tank.

[0013] Furthermore, the device is connected to a vacuum system, which includes a vacuum pipe, a mechanical pump and a diffusion pump, and can provide a vacuum environment for the device.

[0014] Furthermore, a guide rail steel frame is installed at the bottom of the device to support the distillation tank and the medium-temperature resistance furnace. At the same time, the furnace core assembly can move left and right to achieve separation from the distillation tank, thereby facilitating the loading operation.

[0015] Compared with the existing technology, the advantages of the present invention are:

[0016] 1. Through the different temperature control of the medium-temperature resistance furnace and the setting of zoned condensation, the difference in saturated vapor pressure of different substances can be used to achieve the classified collection of oil, metallic lithium and electrolyte in the residue.

[0017] 2. The detachable structure design enables the evaporation tank to be separated from the furnace core, increasing the loading capacity of the evaporation tank and facilitating the loading operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a vacuum distillation apparatus for extracting lithium from residue provided by the present invention;

[0019] Figure 2 This is a schematic structural diagram of the furnace core assembly provided by the present invention;

[0020] Figure 3 This is a schematic structural diagram of the distillation tank provided by the present invention;

[0021] Figure: 1. Distillation tank; 2. Medium-temperature resistance furnace; 3. Furnace core assembly; 4. Oil vapor condensation baffle; 5. Vacuum system; 6. Vacuum tank; 7. Oil collection tank; 8. Guide rail steel frame; 9. Evaporation zone; 10. Primary condensation zone; 11. Transition zone; 12. Secondary condensation zone; 13. Evaporation crucible; 14. Thermal insulation sheet; 15. Electrolyte collector; 16. Condensation hood; 17. Furnace core; 18. Oil cooling zone DETAILED DESCRIPTION

[0022] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] like Figure 1-Figure 3 As shown, a vacuum distillation device for extracting lithium from residue includes a distillation tank 1, a medium-temperature resistance furnace 2 and a furnace core assembly 3. The distillation tank 1 is divided into an evaporation zone 9, a primary condensation zone 10 and a secondary condensation zone 12 according to the phase changes occurring in different areas, which correspond to the areas of different components in the evaporated residue, condensed metallic lithium and condensed oil, respectively, and the primary condensation zone 10 and the secondary condensation zone 12 are connected by a transition zone 11.

[0024] The medium-temperature resistance furnace 2 is located outside the evaporation zone 9 of the distillation tank 1, and is divided into two upper and lower parts of the cover design. The part in contact with the distillation tank 1 is a hard insulation layer. The side wall of the insulation layer is installed with 12 nickel-chromium alloy heating belts, which can provide different heating temperatures for the evaporation zone 9.

[0025] The furnace core assembly 3 is located inside the distillation tank 1 and includes an evaporation component and a condensation component. The evaporation component is located in the evaporation zone 9 and includes an evaporation crucible 13. The evaporation crucible 13 is used to place residue, with a maximum loading capacity of 6 kg, and heat is provided by the medium-temperature resistance furnace 2; the condensation component includes a heat insulation sheet 14, a condensation cover 16 and an oil cooling zone 18. The number of the heat insulation sheets 14 can be selected from 1 to 6. An electrolyte collector 15 is connected and installed to collect the condensed electrolyte. The condensation cover 16 is located in the primary condensation zone 10 and is designed with an opening with an inclination angle of 3-10° to collect the condensed metallic lithium vapor. When the lithium vapor in the residue runs to the condensation cover 16, it will gather on its surface and liquefy into molten lithium metal. A vacuum tank 6 is connected below it. The condensed metallic lithium melt can flow into the vacuum tank 6 along the conduit to extract metallic lithium; the oil cooling zone 18 is located in the secondary condensation zone 12, and an oil vapor condensation baffle 4 is connected above it and an oil collection tank 7 is connected below it to collect the condensed oil vapor.

[0026] The device is connected to a vacuum system 5 , which includes a vacuum pipe, a mechanical pump and a diffusion pump, and can provide a vacuum environment for the device.

[0027] A guide rail steel frame 8 is installed at the bottom of the device to support the distillation tank 1 and the medium-temperature resistance furnace 2. At the same time, the furnace core assembly 3 can move left and right to achieve separation from the distillation tank 1, facilitating the loading operation.

[0028] The implementation principle of the vacuum distillation device for extracting lithium from the residue of this embodiment is as follows: When the metallic lithium in the residue is recovered, 5 kg of the residue is weighed and loaded into the evaporation crucible 13, and the furnace core assembly 3 is automatically controlled by the automatic control system. Figure 1 Slide the device into the distillation tank 1 from left to right via the guide rail and close the flange. Then, open the medium-temperature resistance furnace 2, set the heating temperature to 200°C, and turn on the vacuum system 5 to evacuate the interior of the device to preheat the device. When the vacuum degree is less than 1 Pa, adjust the medium-temperature resistance furnace 2, raise the temperature to 350°C, and keep it warm for 75 minutes to fully volatilize the oil in the residue. The oil vapor evaporates to the oil vapor condensation baffle 4 and condenses, and flows into the oil collection tank 7. When the oil is completely volatilized, continue to raise the temperature to 750°C and keep it warm for 5.5 hours to volatilize the metallic lithium and electrolyte in the residue. After the electrolyte vapor passes through the insulation sheet 14, it condenses on the electrolyte collector 15 before the metallic lithium vapor. After passing through the electrolyte collector 15, the metallic lithium vapor condenses into a metallic lithium melt in the condensation hood 16, and flows along the conduit into the vacuum tank 6, thereby extracting the metallic lithium.

[0029] In the description of the present invention, it should be noted that the terms "left end", "right end", "above", "below", "outside", "inside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0030] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0031] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A vacuum distillation apparatus for extracting lithium from residue, characterized in that: The device comprises: a distillation tank (1), a medium-temperature resistance furnace (2) and a furnace core assembly (3); the distillation tank (1) comprises an evaporation zone (9), a primary condensation zone (10) and a secondary condensation zone (12), which respectively correspond to zones for different components in the evaporation residue, condensed metallic lithium and condensed oil; the medium-temperature resistance furnace (2) is located outside the evaporation zone (9) and can provide different heating temperatures for evaporation; and the furnace core assembly (3) is located inside the distillation tank (1).

2. The vacuum distillation apparatus for extracting lithium from residue according to claim 1, characterized in that: The medium-temperature resistance furnace (2) is divided into two parts, the upper and lower parts, and the part in contact with the distillation tank (1) is a hard insulation layer. The side wall of the insulation layer is equipped with 12 heating belts made of nickel-chromium alloy, which can heat the evaporation zone (9).

3. The vacuum distillation apparatus for extracting lithium from residue according to claim 1, characterized in that: The furnace core assembly (3) comprises an evaporation component and a condensation component. The evaporation component is located in the evaporation zone (9) and comprises an evaporation crucible (13). The evaporation crucible (13) is used to place residue, and the maximum loading capacity is 6 kg.

4. The vacuum distillation apparatus for extracting lithium from residue according to claim 3, characterized in that: The condensation components of the furnace core assembly (3) include a heat insulation sheet (14), a condensation cover (16) and an oil cooling area (18).

5. The vacuum distillation apparatus for extracting lithium from residue according to claim 4, characterized in that: The number of the heat insulation sheets (14) is 1-6, and an electrolyte collector (15) is connected to the heat insulation sheets (14) for collecting condensed electrolyte.

6. The vacuum distillation apparatus for extracting lithium from residue according to claim 4, characterized in that: The condensation hood (16) is located in the primary condensation zone (10) and is designed as an opening with an inclination angle of 3-10 degrees, and is used to collect condensed metallic lithium vapor. A vacuum tank (6) is connected below the condensation hood, and the condensed metallic lithium melt can flow into the vacuum tank (6) along the conduit to extract the metallic lithium.

7. The vacuum distillation apparatus for extracting lithium from residue according to claim 4, characterized in that: The oil cooling zone (18) is located in the secondary condensation zone (12), and is connected to an oil collection tank (7) below the oil cooling zone for collecting condensed oil vapor.

8. The vacuum distillation apparatus for extracting lithium from residue according to claim 6-7, characterized in that: A furnace core (17) is connected between the condensation hood (16) and the oil cooling zone (18), and the furnace core (17) is located in the transition zone (11) of the distillation tank (1).

9. The vacuum distillation apparatus for extracting lithium from residue according to claim 1, characterized in that: The device is connected to a vacuum system (5), which includes a vacuum pipe, a mechanical pump and a diffusion pump, and can provide a vacuum environment for the device.

10. The vacuum distillation apparatus for extracting lithium from residue according to claim 1, characterized in that: A guide rail steel frame (8) is installed at the bottom of the device to support the distillation tank (1) and the medium-temperature resistance furnace (2). At the same time, the furnace core assembly (3) can move left and right to achieve separation from the distillation tank (1) and facilitate loading operations.

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